Just thinking out loud here: is Christianity tied to any particular view of marriage? That is, if the social patterns of marriage changed drastically from what is conventionally acceptable today, and the Church blessed the process, would anything essential to Christianity be lost?

A handful of points:
– Jesus tells us that marriage is an earthly arrangement, not a heavenly one;
– Scripture witnesses to a variety of marriage styles, especially polygamy;
– on the other hand, Scripture also often portrays the heterosexual bond as normative (eg Mt 19.4-6);
– it’s probably the particular virtues involved (fidelity, honesty etc) that are crucial for Christian life;
– in Christian history there have been times (eg medieval era) when marriage was restricted to those who were comparatively wealthy, eg with property, so marriage as such is not a universal;
– more recently, polygamy still seems to be tacitly accepted in some Christian areas, the argument being that monogamy owes more to Roman culture than to Scripture (although there are good scientific arguments for monogamy too).

With this I’m just trying to get clear about what is at stake in the discussion about the blessing of civil unions, and what it would mean if they were called ‘marriage’, and, more broadly, what would happen if a wider culture embraced or accepted a wide variety of “alternative” lifestyles.

My suspicion is that the answers to my opening questions are both ‘No’ and that Christianity can function, flourish and ‘be itself’ in all sorts of diverse contexts.